Alkali metal salts of a cobalt complex of ethylene-bisimino-diacetic acid



Patented July 14, 1953 UITED STATES PATENT OFFICE ALKALI METAL SALTS OF A COBALT COM- FLEX OF ETHYLENE-BISHVIINO-DIACETIC ACID Werner Zerweck and Max Schubert, Frankfurt am Main Fechenheim, Germany, assignors to Cassella Farbwerke Mainkur Aktiengesellschaft, Frankfurt am Main Fechenheim, Germany, a company of Germany No Drawing. Application February 20, 1951, Se-

rial No. 211,979. In Germany March 6, 1950 1 Claim. 1 This invention relates to new therapeuticals containing cobalt. I

These new compounds correspond probably to the formula:

To a solution of 291 parts of cobaltous nitrate [C(NO3)2.6H2O=1 mole] in about 1500 parts of water there are added while stirring 2 moles of a- 11 solution of potassium hydroxide. The precipitated cobaltous hydroxide is filtered by suction until the nitrate reaction is negative. From the paste thus obtained a suspension is formed with 2000 parts of water and this suspension is stirred with 292 parts of ethylene-bisimino-diacetic acid. 2 moles of a 10 11 solution of potassium hydroxide are then allowed to flow in, whereby a limpid violet solution is formed.

In order to isolate the salt, the solution is concentrated by vacuum evaporation to a volume of about 750 parts and an equal portion of methanol is added under stirring. A crystalline mass is thus formed, consisting of slightly rose-colored laminae, which is filtered by suction, washed 2 with methanol and dried at -70 C. According to an elementary analysis the product is of the following composition:

C10H1208N2COK2.3H2O

Example 2 A solution of 238 parts of cobalt chloride (CoC12.6H2O=1 mole) in 1500 parts of Water'is heated to C. and a 10% solution of sodium carbonate is allowed to flow to it until an alkaline reaction is obtained. The precipitated cobalt carbonate is allowed to react with ethylene-bisimino-diacetic acid and 2 moles of caustic soda lye in an analogous manner as described in Example 1. After working it up in exactly the same way, the complex cobalt-disodium salt is obtained in form of slightly violetcolored laminae having the formula:

Ci0H1208N2CONaa3H2O We claim: As new compounds the complex cobalt compounds of ethylene-bisimino-diacetic acid corresponding to the formula:

WERNER ZERWECK. MAX SCHUBERT.

References Cited in the file of this patent SchwarzenbachI-Ielvetica Chimica Acta, vol. 32, page 848, May 1949.

Brintzinger et al.Zeitschrift fur Anorganische and Allgemeine Chemie, vol. 251, pages 285-294 (1943).

Pfeifier et al.Ber. v01. 76, pages 847-855. 

